domain-task also needs TypeScript 2+ because of whatwg-streams

Author: SteveSandersonMS

src/Microsoft.AspNetCore.SpaServices/npm/domain-task/package.json

@@ -22,6 +22,6 @@
   },
   "devDependencies": {
     "rimraf": "^2.5.4",
-    "typescript": "^1.8.10"
+    "typescript": "^2.0.0"
   }
 }